Inspection device and inspection method

ABSTRACT

According to an embodiment, an inspection device comprises a moving body that includes; a moving main body which moves in contact with a first structure; arms attached to the moving main body; an arm driver to drive the arms; and a detector attached to the moving main body or the arms to inspect the second structure. The arms each can selectively take a pressed position and a detached position. When the moving body is moved, at least one of the arms are in the pressed position and pressed to the second structure, and the moving body is supported by the first and second structures.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2017-251812, filed on Dec. 27, 2017; theentire content of which is incorporated herein by reference.

FIELD

The present embodiments relate to an inspection device provided with amoving body movable along a to-be-inspected object, and an inspectionmethod using the inspection device.

BACKGROUND

A rotary electric machine such as an electric power generator requiresmaintenance including inspection of electrical and mechanical soundnessusing inspection devices. In such an inspection, the inspection devicehas to access the outer surface of the rotor or the inner surface of thestator. Typically, the rotor is extracted from the stator forinspection, because the gap between the rotor and the stator is narrowwhen the rotor is inserted in the stator. However, the extraction of therotor from the stator requires a lot of labor and time.

Meanwhile, inspection technology is being developed where an inspectiondevice is moved in the narrow annular gap between the rotor and thestator while the rotor remains inserted in the stator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing whole structure of an inspectiondevice according to a first embodiment of the invention.

FIG. 2 is a schematic plan view of a moving body shown in FIG. 1.

FIG. 3 is a block diagram showing functional structure of a controlconsole shown in FIG. 1.

FIG. 4 is a schematic view showing a situation where the moving body anda base unit are located when the inspection device of FIG. 1 is appliedto an inspection of a rotary electrical machine.

FIG. 5 is a plan view along arrows V-V of FIG. 4.

FIG. 6 is a plan view showing a situation where the moving body and thebase unit of FIG. 4 are engaged.

FIG. 7 is a flow chart showing a sequence of an inspection method usingthe inspection device according to the first embodiment.

FIG. 8 is an explanatory view showing movements of arms while the movingbody of FIG. 1 moves axially on an outer surface of a rotor main body.

FIG. 9 is an explanatory view showing movements of the arms where themoving body of FIG. 1 is drawn out axially when electric power orair-pressure has been lost during axial movement of the moving body onthe outer surface of the rotor main body.

FIG. 10 is a schematic view showing whole structure of an inspectiondevice according to a second embodiment of the invention.

DETAILED DESCRIPTION

An object of the embodiments is to provide an inspection device and aninspection method where a moving body is moved and inspection of theto-be-inspected object is inspected efficiently with small labor.

According to an aspect of the present invention, there is provided aninspection device comprising: a moving main body to be inserted in a gapbetween a first structure and a second structure facing outside of thefirst structure; a moving driver to drive the moving body on and alongthe first structure; at least two arms attached to the moving main body;an arm driver to drive the arms so that the arms each selectively takesa pressed position where the arm expands toward the second structure tobe pressed to the second structure, and a detached position where thearm is detached from the second structure; and at least one detectorattached to at least one of the moving main body and the arms, toinspect at least one of the first and second structures, wherein the armdriver is configured to drive at least one of the at least two arms tobe maintained in the pressed position when the moving main body ismoved.

According to another aspect of the present invention, there is providedan inspection method comprising: a moving step of moving a main bodyalong a first structure, while the main body is disposed in a gapbetween the first structure and a second structure facing outside of thefirst structure; an arm driving step of driving arms so that the atleast two arms each selectively takes a pressed position where the armextends toward the second structure to be pressed to the secondstructure, and a detached position where the arm is detached from thesecond structure; and an inspection step of inspecting at least one ofthe first and second structures, by at least one detector attached to atleast one of the moving main body and the arms, wherein the arm drivingstep is conducted while at least one of the at least two arms aremaintained in the pressed position.

Embodiments of the invention are now described referring to drawings.Same or similar parts are assigned common reference numerals, andrepetitive explanation is omitted.

First Embodiment

FIG. 1 is a schematic view showing whole structure of an inspectiondevice according to a first embodiment of the invention. FIG. 2 is aschematic plan view of a moving body shown in FIG. 1. FIG. 3 is a blockdiagram showing functional structure of a control console shown inFIG. 1. FIG. 4 is a schematic view showing a situation where the movingbody and a base unit are located when the inspection device of FIG. 1 isapplied to an inspection of a rotary electrical machine. FIG. 5 is aplan view along arrows V-V of FIG. 4. FIG. 6 is a plan view showing asituation where the moving body and the base unit of FIG. 4 are engaged.

The inspection device according to the first embodiment has: a movingbody 10, a base unit 11, a control console 12, a cable 35 connecting themoving body 10 and the base unit 11, and a cable 36 connecting the baseunit 11 and the control console 12. The moving body 10 can move in anaxial direction on the outer surface of the rotor main body 109 in anannular gap 103. The gap 103 is formed between a rotor main body (firststructure) 109 of a rotor 101 of a rotary electrical machine 100 and astator (second structure) 102 which is disposed outer side of the rotormain body 109 facing the rotor main body 109. The cables 35 and 36 maybe connected with relays or may be a continuous cable. In the followingexplanation, basically, the stator 102, which is the second structure,is the to-be-inspected object. However, the rotor main body 109 which isthe first structure may be the to-be-inspected object. Theto-be-inspected object may be either one or both of the stator 102 thatis the second structure and/or the rotor main body 109 that is the firststructure.

The expression of “plan view” is used here only because of conveniencefor explanation. The structure and the operation do not depend on thedirection of gravity. For example, in FIG. 1, the rotor main body 109 isshown to be disposed below the moving body 10, while the stator 102 isshown to be disposed above the moving body 10. However, in practice,such a situation may not be always maintained.

The rotary electrical machine 100 may be, for example, a hydrogencooling electric power generator. As shown in FIG. 4, the rotor 101includes: a rotor shaft 104; a rotor main body 109 that is formed in aunit coaxially with the rotor shaft 104 and is provided with rotorwindings; and circular end rings 105 that are disposed axially outersides of the rotor main body 109 sandwiching the rotor main body 109.The rotor shaft 104 constitutes axially outer sides of the rotor mainbody 109 in the rotor 101. The rotor shaft 104 is provided with bearings106 to support the rotor 101 as a whole, and a flange to be coupled withan external machine such as a turbine. The outer diameter of the rotormain body 109 is larger than the outer diameter of the rotor shaft 104.The rotor main body 109 includes; a rotor core, rotor windings (notillustrated) disposed in a plurality of axially extending slots formedalong the outer peripheral surface of the rotor core; and wedges (notillustrated) to hold the rotor windings in the slots. In many cases, therotor main body 109 except for the wedges and the rotor windings, andthe rotor shaft 104 of the rotor 101 are formed in a unit by forging,for example.

The stator 102 has a hollow circular cylindrical shape, and is disposedsurrounding radially outside of the rotor main body 109. Although detailillustration is omitted, the stator 103 has: a stator core formed with aplurality of electromagnetic steel plates stacked in the axialdirection; a stator windings disposed in a plurality of slots extendingin axial direction formed along the inner surface of the stator core;and wedges to hold the stator windings in the slots.

A frame 107 is disposed to support and cover the stator 102. Thebearings 106 are supported by the frame 107. A closed space is formed inthe frame 107, and the closed space is filled with cooling medium suchas hydrogen gas. A fan 108 is attached to the rotor shaft 104 in theframe 107, by which the cooling medium in the frame 107 is forcefullycirculated.

Annular baffles 111 are disposed extending along inner peripheral of thestator 102. The baffles 111 protrude radially inward in the gap 103 fromthe stator 102 side, and divide the annular gap 103 into a plurality ofannular sections arrayed in the axial direction, so that axial flow ofthe cooling medium in the gap 103 is suppressed. However, the tips ofthe baffles do not touch the outer surface of the rotor main body 109,and the moving body 10 can pass axially the gap between the tips of thebaffles 111 (the inner peripheral surfaces of the baffles 111 facing therotor 101) and the outer peripheral surface of the rotor main body 109.

The base unit 11 is attached to outer peripheral surface of one of theend rings 105. The base unit 11 can move (rotate) circumferentially onthe outer peripheral surface of the end ring 105. The moving body 10 canmove axially so that it can be attached to and detached from the baseunit 11. When the moving body 10 is attached to the base unit 11 asshown in FIG. 6, the moving body 10 can move (rotate) along the end ring105 in a peripheral direction.

As shown in FIGS. 1 and 2, the moving body 10 has a moving main body 30,and mounted objects 25 mounted on the moving main body 30. The movingbody 10 may be a vehicle, for example.

The moving body 10 can move at least in the direction of the axis of therotary electrical machine 100. Crawlers 31 are attached to the movingmain body (vehicle body) 30. The crawlers 31 are means for moving themoving body 10, pressed to and in contact with the outer peripheralsurface of the rotor main body 109 which is the first structure. Thecrawlers 31 are driven by their wheels which are driven by a movingdriver 17. Thus, the moving body 10 can be driven forward, backward andbe stopped. The rotation speeds of the right and left crawlers 31 can beadjusted independently by the moving driver 17, so that the forward andbackward moving direction of the moving body 10 can be adjusted.Alternatively, the moving means such as wheels can be used instead ofthe crawlers 31 or tracklayers.

The mounted objects 25 are mounted on the moving main body 30. Themounted objects 25 include a first arm 14, a second arm 15, a third arm16, the moving driver 17, an arm driver 18, a transmitter-receiver 19, acamera 20, a distance meter 21, a moving distance meter 22, a lightingequipment 23 and a detector 26.

The first, second and third arms 14, 15, 16 are swingable around axes 14a, 15 a and 16 a, respectively, with respect to the moving main body 30.The arm driver 18 drives the first, second and third arms 14, 15, 16 andchanges the shapes such as the positions of the arms with respect to themoving main body 30. The first, second and third arms 14, 15, 16 aredriven by the arm driver 18, and can each take a pressed position and adetached position. In the pressed positions, the arms are extended fromthe moving main body 30 toward the inner peripheral surface of thestator 102. In the detached positions, the arms are folded toward themoving main body 30 and detached from the stator 102.

The arm driver 18 includes a first spring 14 b, a second spring 15 b,and a third spring 16 b which bias the first, second and third arms 14,15, 16, respectively, in directions of the pressed positions or thedetached positions. The arm driver 18 further includes electric motorsor air pressure drive mechanisms (not illustrated) to drive the first,second and third arms 14, 15, 16 each toward the pressed position or thedetached position against the bias force (restoring force) of the first,second and third springs 14 b, 15 b and 16 b. The arm driver 18 candrive the first, second and third arms 14, 15, 16 each to any one of thepressed position and the detached position.

The first spring 14 b and the third spring 16 b bias the first arm 14and the third arm 16, respectively, toward their pressed positions. Thesecond spring 15 b biases the second arm 15 toward its detachedposition. Therefore, if electric power or air pressure source is lostdue to an accident or a failure, the first arm 14 and the third arm 16would take their pressed positions by the first spring 14 b and thethird spring 16 b, respectively, and the second arm 15 would take itsdetached position by the second spring 15 b.

First, second and third rollers 14 c, 15 c, 16 c are attached to leadingtips of the first, second and third arms 14, 15, 16, respectively. Whenthe moving body 10 moves while the first, second and third arms 14, 15,16 are in their pressed positions, the first, second and third rollers14 c, 15 c, 16 c rotate while they are pressed against the inner surfaceof the stator 102, so that the moving body 10 can move smoothly.

The first, second and third arms 14, 15, 16 are inclined to a samedirection (to the upper left in FIG. 1, for example) with respect to theaxial direction. The inclination direction is set so that the positionsof the arms can be easily changed when moving main body 30 is pulled inthe axial direction with the cable 35. Detailed operation will beexplained later referring to FIG. 9.

The distance meter 21 measures the distance to the stator 102. Themoving distance meter 22 measures the moved distance of the moving body10 by measuring the movements of the crawlers 31, for example. Thecamera 20 obtains image information of the stator 102, for example. Thelighting equipment 23 illuminates the shot area of the camera 20 so asto obtain clear image.

The detector 26 detects the rotor main body 109 which is the firststructure and/or the stator 102 which is the second structure. Thedetector 26 may include an ultrasonic flaw detector and/or a camera.

Inspection of the rotor main body 109 may include ultrasonic flawdetection of teeth (not illustrated) each formed between slotscontaining the rotor windings or of wedges disposed outer side in theslots, using an ultrasonic flaw detector, and/or visual inspection ofradial through holes (not illustrated), using a camera.

Inspection of the stator 102 may include wedge loosening inspectionwhere loosening of wedge (not illustrated) is inspected by detectingsound after a hammering of the wedge disposed outer side of the statorwindings. Alternatively, the inspection of the stator 102 may include anEL-CID (electromagnetic core imperfection detection) test of the statorcore where failure current is detected in a case of a short circuit inthe stator core by generating magnetic flux in the stator core.

The detector 26 may not be attached directly to the moving main body 30,but may be attached to the arms 14, 15, 16 described above, especiallyin a case of inspection of the stator 102, for example. Alternatively,an additional special arm may be attached to the moving main body 30 andthe detector may be attached to the additional special arm to inspectthe rotor main body 109 and the stator 102. Specifically, the detector26 for inspecting the stator 102, such as the detector 26 for statorwedge loosening inspection and EL-CID tests of the stator core, ispreferably attached to the above described arms 14, 15, 16.

The detector 26 installed on the moving body 30 may include all of theultrasonic flaw detection devices for the teeth or the wedges of therotor main body 109, the camera for visual inspection of the vent holesin radial direction of the rotor main body 109, the hammer forinspecting the loosening of the wedges of the stator core and theapparatus for EL-CID tests. Alternatively, some of the detectorsdescribed above may be installed on the moving main body 30.Specifically, when the many devices for inspections or tests areinstalled on the moving main body 30 as the detectors 26, theinspections and tests may be conducted automatically.

The moving driver 17, the arm driver 18, the camera 20, the distancemeter 21, the moving distance meter 22 and the detector 26 arecontrolled or operated by the control console 12, and the obtained dataare processed by the control console 12. The information signals areexchanged through the cables 35, 36. All or some of the informationsignals may be exchanged wirelessly via the transmitter-receiver 19.Alternatively, at least part of the control console 12 including the armdriver controller 62 (described later in detail), for example, may beinstalled on the moving main body 30 so that the moving body 10 can becontrolled and operated autonomously. Furthermore, the control console12 as a whole may be installed on the moving main body 30.

The control console 12 includes an input unit 40, a computing controlunit 41, a storage 42, a display 43 and a transmitter-receiver 44, asillustrated in FIG. 3. The control console 12 may be a multipurposecomputer such as a personal computer.

The input unit 40 includes a shape information input unit 50, aninspection location information input unit 51, an inspection iteminformation input unit 52, a tolerance range information input unit 53and an inspection start command input unit 54.

The shape information input unit 50 is used to input shape informationof the shapes of the stator 102 which is the object to be inspected andthe second structure, and the rotor main body 109 which is the firststructure to support the moving body 10. The shape information is basedon the design information or actually measured information of the rotaryelectric machine 100. When the shape information is obtained by actualmeasurement, data is obtained using the camera 20 and the distance meter21, for example, while the moving body 10 is driven manually, and theshape information is obtained from the obtained data.

The inspection location information input unit 51 is used to inputinspection location information in relation to the shape information.The inspection item information input unit 52 is used to input theinspection items in relation to the inspection location information. Theinspection item information may include information of the area to beinspected. The tolerance range information input unit 53 is used toinput tolerance range information that is the basis for deciding theinspection result is acceptable or not.

The inspection start command input unit 54 is used to input theinspection start command.

The computing control unit 41 includes a moving control unit 61, an armdriver control unit 62, an inspection control unit 63, a moving bodylocation calculation unit (a moving body location detection unit) 64, animage recognition location calculation unit 65 and a decision unit 66.

The moving control unit 61 controls the moving driver 17 installed onthe moving main body 30 so that the movement of the moving body 10 iscontrolled. The arm driver control unit 62 controls the arm driver 18installed on the moving main body 30 so that the movement or operationof the arms 14, 15, 16. The inspection control unit 63 controls thedetector 26 etc.

The moving body location calculation unit 64 calculates current locationof the moving body 10 based on the history record of the moving bodylocation information, the shape information and the moved (traveled)distance obtained by the moving distance meter 22 installed on themoving main body 30 etc. The image recognition location calculation unit65 calculates current location of the moving body 10 based on thehistory record of the moving body location information, the shapeinformation and the image obtained by the camera 20 installed on themoving body 30. In calculation of the current location of the movingbody 10, the result of the moving body location calculation unit 64 andthe result of the image recognition location calculation unit 65 may becombined to obtain higher preciseness.

The decision unit 66 decides whether the inspection result is acceptableor not based on the tolerance range information.

The storage 42 includes a shape information storage unit 71, aninspection location information storage unit 72, an inspection iteminformation storage unit 73, a moving body location information storageunit 74, an inspection result information storage unit 75, an imageinformation storage unit 76 and a tolerance range information storageunit 77.

The shape information storage unit 71 stores the shape information inputwith the shape information input unit 50. The inspection locationinformation storage unit 72 stores the inspection location informationwith the inspection location information input unit 51. The inspectionitem information storage unit 73 stores the inspection item informationwith the inspection item information input unit 52. The moving bodylocation information storage unit 74 stores the moving body locationinformation calculated by the moving body location calculation unit 64.The inspection result information storage unit 75 stores the inspectionresults of the detector 26 etc. and also stores the results of thedecision by the decision unit 66. The image information storage unit 76stores the image obtained by the camera 20 etc. The tolerance rangeinformation storage unit 77 stores the tolerance range information inputwith the tolerance range information input unit 53.

The display 43 includes a decision result display 80. The decisionresult display 80 displays the decision result of the decision unit 66.The display 43 may include a display unit for displaying the location ofthe moving body 10 calculated by the moving body location calculationunit 64 and/or the current or present image shot by the camera 20, etc.in addition to the decision result display 80.

The transmitter-receiver 44 of the control console 12 exchange signalswith the transmitter-receiver 19 which is included in the mountedobjects 25. The signal exchange may be conducted via the cables 35 and36, or, alternatively, wirelessly.

FIG. 7 is a flow chart showing a sequence of an inspection method usingthe inspection device according to the first embodiment. First, theshape information, the inspection location information, the inspectionitem information and the tolerance range information are input with theshape information input unit 50, the inspection location informationinput unit 51, the inspection item information input unit 52 and thetolerance range information input unit 53, and they are stored in theshape information storage unit 71, the inspection location informationstorage unit 72 and the inspection item information storage unit 73,respectively (Step S10). Then, the operator inputs the inspection startcommand to the inspection start command input unit 54 (Step S11). Afterthat, the inspection device automatically conducts the inspection. Inthe present embodiment, the object range to be inspected is a wholecircumferential surface of the stator 102, for example.

When the inspection start command is input in Step S11, the inspectionstart location is automatically set based on the inspection iteminformation stored in the inspection item information storage unit 73,and the base unit 11 moves to the peripheral position (inspection startperipheral location) of the slot corresponding to the inspection startlocation (Step S12). The inspection start location may be setautomatically. Alternatively, the inspection start location may beincluded in the inspection item information input with the inspectionitem information input unit 52, or may be input in advance when theinspection start command is input in Step S11 When the base unit 11 ismoved to the inspection start peripheral location, the moving body 10and the base unit 11 are separated (Step S13). Then, the moving body 10moves away axially from the end ring 105 which has been engaged with themoving body 10 via the base unit 11.

Then, the moving body 10 moves axially to the inspection location by thecontrol of the moving control unit 61 and the arm driver control unit 62(Step S14). After the moving body 10 has reached the inspectionlocation, the inspection is conducted by the control of the inspectioncontrol unit 63 (Step S15). Then, the decision unit 66 decides theinspection results (Step S16). The result of the decision is displayedon the decision result display 80, and stored in the inspection resultinformation storage unit 75 (Step S17).

Then, it is decided whether the moving body 10 has reached the base unit11 (Step S18). If the moving body 10 has not reached the base unit 11(in a case of NO in Step S18), the procedure returns to Step S14. If themoving body 10 has reached the base unit 11 (in a case of YES in StepS18), the moving body 10 and the base unit 11 are connected (Step S19).

Next to Step S19, it is decided whether the base unit 11 has moved fullaround the end ring 105 (or all the stipulated area to be inspected hasbeen inspected in a case where the area to be inspected is stipulated inadvance in the inspection item information input with the inspectionitem information input unit 52) (Step S20). If the base unit 11 hasmoved full around the end ring 105 (or all the stipulated area to beinspected has been inspected in a case where the area to be inspected isstipulated in advance in the inspection item information input with theinspection item information input unit 52) (in a case of YES in StepS20), the operation ends. If the base unit 11 has not moved full aroundthe end ring 105 yet (or all the stipulated area to be inspected has notbeen inspected yet in a case where the area to be inspected isstipulated in advance in the inspection item information input with theinspection item information input unit 52) (in a case of NO in StepS20), the base unit 11 is moved with the moving body 10 for a stipulateddistance in the peripheral direction on the end ring 105 (Step S21).Then, the procedure goes back to Step S13, and the moving body 10 isseparated from the base unit 11. Then, the inspection procedure fromStep S14 is continued at a different peripheral location apart from theprevious peripheral location

As described above, the inspection device automatically conductsinspection procedure after the inspection start signal input (Step S11).

In the example shown in FIG. 7, the whole surface of the stator 102 isstipulated in advance as the area to be inspected or the area to beinspected is included in the inspection item information input inadvance with the inspection item information input unit 52.Alternatively, when the inspection start command is input in Step S11 ofFIG. 7, the area to be inspected may be stipulated in advance, and inStep S20, it may be decided whether all the stipulated area to beinspected has been inspected or not.

In a case where the base unit 11 is attached to only one of the two endrings 105 disposed at both axial ends of the rotor main body 109 asshown in FIG. 4, the moving body 10 goes back on the same axial route tothe same base unit 11. Alternatively, base unit 11 may be attached toeach of the two end rings 105, although such a situation is notillustrated. In such a situation, the moving body 10 would be engagedwith the two base units alternately, and the moving body 10 would movein both axial directions alternately and the inspection is continuedwithout moving on the same axial route repeatedly. Thus, the inspectionwould be conducted more efficiently.

Next, the operation of the arms of the inspection device according tothe first embodiment is described in detail below.

FIG. 8 is an explanatory view showing movements of the arms while themoving body 10 of FIG. 1 moves axially on an outer surface of the rotormain body 109. In FIG. 8, the moving body 10 moves in an axial direction(left and right direction in FIG. 8) along the rotor main body (firststructure) 109 in the annular gap 103 between the inner peripheralsurface of the stator (the object to be inspected; the second structure)102 and the outer peripheral surface of the rotor main body 109. In theillustrated example, the moving body 10 moves to the left (as shown asan arrow A) as shown in (a), (b), (c), (d) and (e) of FIG. 8 in thisorder. The circular annulus baffle 111 formed in the inner surface ofthe stator 102 protrudes toward rotor main body 109.

At the stage of (a) of FIG. 8, the first, second and third arms 14, 15,16 are all in the pressed positions. The tips of the first, second andthird arms 14, 15, 16 press the inner peripheral surface of the stator102, and the inner peripheral surface of the stator 102 presses the tipsof the first, second and third arms 14, 15, 16 as a reaction. Thus, thecrawlers 31 of the moving body 10 are pressed to the outer peripheralsurface of the rotor main body 109, and the outer peripheral surface ofthe rotor main body 109 presses the crawlers 31 as a reaction. Thus, themoving body 10 is supported by the stator 102 and the rotor main body109.

At the stage of (b) of FIG. 8, the second and third arms 15, 16 are inthe pressed positions, while the first arm 14 is in the detachedposition. Thus, interference between the first arm 14 and the baffle 111can be avoided.

At the stage of (c) of FIG. 8, the first and third arms 14, 16 are inthe pressed positions, while the second arm 15 is in the detachedposition. Thus, interference between the second arm 15 and the baffle111 can be avoided.

At the stage of (d) of FIG. 8, the first, second and third arms 14, 15,16 are all in the pressed positions.

At the stage of (e) of FIG. 8, the first and second arms 14, 15 are inthe pressed positions, while the third arm 16 is in the detachedposition. Thus, interference between the third arm 16 and the baffle 111can be avoided.

With the sequential operation described above, the moving body 10 canpass the inner side of the baffle 111 without interferences between thefirst, second and third arms 14, 15, 16 and the baffle 111. At the sametime, the moving body 10 is supported by the stator 102 and the rotormain body 109, since at least two of the three arms 14, 15, 16 are inthe pressed positions.

Next, a situation is explained where the electric power source or theair pressure is lost by an accident or a failure while the moving body10 is moving axially on the rotor main body 109. In such a situation,the first arm 14 and the third arm 16 become in the pressed positionsowing to the restoring forces of the first spring 14 b and the thirdspring 16 b, while the second arm 15 becomes in the detached positionowing to the restoring force of the second spring 15 b. Even in such asituation, the two arms are in the pressed position, and the moving body10 remains being supported by the stator 102 and the rotor main body109.

In such a situation, if the moving body 10 cannot move by itself, themoving body 10 can be drawn out of the gap (annular space) 103 bypulling out the cable 35 axially toward the base unit 11.

FIG. 9 is an explanatory view showing movements of the arms where themoving body 10 of FIG. 1 is drawn out axially when electric power orair-pressure has been lost during axial movement of the moving body 10on the outer surface of the rotor main body 109. In the illustratedexample, the moving body 10 is drawn and moves to the right (as shown asan arrow B) as shown in (a), (b), (c) and (d) of FIG. 9 in this order.

FIG. 9(b) shows a situation where the third arm 16 is passing the baffle111. In this situation, the third arm 16 is in the pressed positionowing to the restoring force of the third spring 16 b. However, when theroller 16 c attached to the tip of the third arm 16 touches the baffle111, the third arm 16 changes its shape or position against therestoring force of the third spring 16 b, and the third arm 16 can passthe baffle 111.

FIG. 9(c) shows a situation where the third arm 16 has just passed thebaffle 111. Since the third arm 16 has passed the baffle 111, the thirdarm 16 extends to the pressed position by the restoration force of thethird spring 16 b.

FIG. 9(d) shows a situation where the first arm 14 is passing the baffle111. In this situation, the first arm 14 is in the pressed positionowing to the restoring force of the first spring 14 b. However, when theroller 14 c attached to the tip of the first arm 14 touches the baffle111, the first arm 14 changes its shape or position against therestoring force of the first spring 14 b, and the first arm 14 can passthe baffle 111.

As understood from the above description, it is important that the firstarm 14 and the third arm 16 are inclined to a same direction. Thus, thefirst arm 14 and the third arm 16 can change their shape when the movingmain body 30 is moved in an axial direction by pulling out the cable 35.

In the above explained example, the moving body 10 is moved by pullingout the cable 35. Alternatively, the moving body 10 may be moved bypulling out a special tow rope or a tow rod (not illustrated) which aredifferent from the cable 35.

As described above, according to the inspection device of the presentembodiment, the required information is input through the inspectionlocation information input unit 51, the inspection item informationinput unit 52 and the tolerance range information input unit 53, and theinspection start command is input through the inspection start commandinput unit 54. Then, the moving body 10 moves automatically to theinspection location, the required inspection is automatically conducted,and the inspection results are decided automatically whether they areacceptable or not. Thus, reliable and speedy inspection can be conductedwith shorter time and smaller labor.

In the above explained example, the arm driver control unit 62 of thecontrol console 12 controls the arm driver 18 installed on the movingmain body 30 so that at least two of the three arms are always in thepressed position and remain pushing the stator 102. Alternatively, theremay be provided only two arms and at least one of the two arms alwaysremain pushing the stator 102. Such a case may be realized by omittingthe second arm 15 in the first embodiment described above.

In such a case, the arm driver 18 installed on the moving main body 30is controlled by the arm driver control unit 62 of the control console12 so that at least one of the two arms remain in the pressing position.Thus, the moving body 10 is supported by reactive force of the at leastone arm in the pressed position that pushes the stator 102 or the secondstructure, and by reactive force of the moving body 10 pushing the firststructure or the rotor main body 109, in the gap between the rotor mainbody 109 and the stator 102.

Second Embodiment

FIG. 10 is a schematic view showing whole structure of an inspectiondevice according to a second embodiment of the invention. The secondembodiment is a variant of the first embodiment, and a detector (seconddetector) 90 instead of the roller is attached to the tip of the secondarm 15. In this case, the tip of the second arm 15 may have a functionof support of the moving body 10 by pressing the stator 102, or may nothave such a support function. In the case where the tip of the secondarm 15 is pressed to the stator 102 to support the moving body 10, aroller is preferably attached to the tip of the second arm 15 inaddition to the detector 90. In FIG. 10, the second arm 15 is inclinedto the same direction as the first and third arms 14, 16 with respect tothe direction of the axis of the rotor main body 109. Alternatively, thesecond arm 15 may be inclined to the opposite direction to theinclination direction of the first and third arms 14, 16.

The detector 90 is preferably for inspection of the stator 102. Thedetector (the second detector) 90 may include either one or both of setsof inspection devices for inspecting loosening of the wedges (notillustrated) disposed on outer peripheral side of the stator windings,and an EL-CID test apparatus for testing the stator core. The sets ofinspection devices for inspecting loosening of the wedges may include ahammer and an acceleration sensor or an acoustic sensor. The looseningof the wedges may be inspected by hitting the wedges with the hammer anddetecting the sound with the acceleration sensor or the acoustic sensor.The EL-CID test apparatus may include a magnetic flux forming coil and afault current detector. The detector 90 may be attached to the tip ofthe second arm 15.

The detector (the first detector) 26 is attached to the moving main body30 of the moving body 10 of the inspection device of the secondembodiment in a similar way as in the first embodiment. The detector(the first detector) 26 is preferable to inspect the rotor main body109. An ultrasonic fault detector for inspecting ultrasonic faultdetection of teeth between slots of the rotary main body 109, and acamera for visual inspection of the radial vent holes (not illustrated)may be installed on the moving main body 30.

The first arm 14 and the third arm 16 are arranged in this embodiment sothat they are inclined in the same direction in respect to the axialdirection of the rotary main body 109, in a similar way as in the firstembodiment. The first and third rollers 14 c, 16 c are attached to thetips of the first and third arms 14, 16, respectively. The first spring14 and the third spring 16 b bias the first arm 14 and the third arm 16,respectively, toward the inner peripheral surface of the stator 102 tothe pressed state. Thus, when the moving body 10 moves with the firstand third arms 14, 16 in the pressed positions, the first and thirdrollers 14 c, 16 c are pressed to the peripheral inner surface of thestator 102 and rotate. Thus, if the electric power source or the airpressure is lost, the first arm 14 and the third arm 16 become in thepressed positions owing to the first spring 14 b and the third spring 16c, and the moving body 10 is supported there. Especially, in the presentembodiment, the first arm 14 and the third arm 16 which are arranged onboth ends of the plurality of arms attached to the moving main body 30become in the pressed position, when the electric power source or theair pressure is lost. Thus, the moving body 10 is securely supportedeven in the case of power failure or air pressure loss.

The second spring 15 b biases the second arm 15 to the detachedposition. The detector 90 is attached to the tip of the second arm 15.Thus, if the electric power or the air pressure is lost due to anaccident or a fault, the second arm 15 takes the pressed position owingto the second spring 15 b, and is detached from the inner surface of thestator 102. Then, the detector (the second detector) attached to the tipof the second arm 15 would be contained in the moving main body 30.

In the present embodiment, when the electric power or the air pressurefor driving the arms are lost during the axial movement of the movingbody 10 on the outer peripheral surface of the rotor main body 109, andwhen the moving body 10 is drawn out, the first arm 14 and the third arm16 take the pressed positions owing to the first spring 14 b and thethird spring 16 b, while the second arm 15 to which the detector (thesecond detector) 90 is attached takes the detached position owing to thesecond spring 15 b, as in the first embodiment. Since the first arm 14and the third arm 16 are inclined in the same direction with respect tothe axial direction of the rotor main body 109, the moving main body 30can be drawn to move axially with shape changes of the first arm 14 andthe third arm 16, as in the first embodiment. In such a situation, thesecond arm 15 detaches from the inner surface of the stator 102 owing tothe second spring 15 b, and the detector (the second detector) 90attached to the tip of the second arm 15 is housed in the moving mainbody 30, so that the moving body 10 can move without causing any failureor damage of the detector (the second detector) 90 attached to the tipof the second arm 15 which might otherwise hit the stator 102.

Other Embodiments

In the above explanation, the object to be inspected is the secondstructure that is the stator 102, and the moving body 10 moves along theouter surface of the first structure that is the rotor main body 109.Alternatively, the object to be inspected may be the first structurethat is the roto main body 109 and the moving body 10 may move along theinner surface of the second structure that is the stator 102.Furthermore, the object to be inspected may not be a rotary electricalmachine.

As a modification of the above explained examples, the mounted objects25 to be mounted on the moving main body 30 may include a controller(not illustrated), and part of the functions of the control console 12may be included in the controller in the moving main body 30. The sizeand weight of the moving body 10 of such a structure may be increased.However, the traffic of the signals exchanged through the cables 35, 36would be decreased and the speed of the control would be increased.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. An inspection device for inspecting a turbinegenerator including a rotor main body and a stator facing outside of therotor main body, the device comprising: a moving main body to beinserted in a gap between the rotor main body and the stator, the movingmain body being connected with a cable extending in an outer directionof the gap, the cable connected at an end of the moving main body; amoving driver in the moving main body to drive the moving main body onand along the rotor main body; at least two arms attached to the movingmain body; first and second springs attached to the moving main body,each of the first and second springs biasing each arm for expandingtoward the stator in a state that each arm contacts the stator and thatis inclined toward a direction opposite to the end of the moving mainbody; an arm driver to drive the arms so that the arms each selectivelytakes a pressed position where the arm expands toward the stator to bepressed to the stator, and a detached position where the arm is detachedfrom the stator; and at least one detector attached to at least one ofthe moving main body and the arms, to inspect at least one of the rotormain body and the stator, wherein when the arm driver is operable, themoving main body moves itself on and along the rotor main body, whilethe moving main body moves and before one of the arms strikes a baffleof the stator, one of the arms is located in the detached position bythe arm driver against a force of the first spring and the other arm ismaintained to contact the stator by a force of the second spring, andwhen the arm driver is inoperable, the moving main body is pulled out ofthe gap by the cable on and along the rotor main body and when one ofthe arms strike the baffle, the one of the arms is pushed down towardthe rotor main body by the baffle pushing the inclination of one of thearms against a force of the first spring and the other arm is maintainedto contact the stator by a force of the second spring.
 2. The inspectiondevice according to claim 1, further comprising: a roller attached totip of at least one of the at least two arms, the roller beingconfigured to rotate being pressed to the stator while the moving mainbody moves along the rotor main body.
 3. The inspection device accordingto claim 1, further comprising: a moving body location detection unitfor detecting moving body location information indicating location ofthe moving main body, wherein the arm driver is configured to drive thearms based on shape information indicating shapes and sizes of the rotormain body and the stator, and the location information indicatinglocation of the moving main body detected by the moving body locationdetection unit.
 4. The inspection device according to claim 3, whereinthe moving body location detection unit includes a moving distance meterfor measuring moved distance of the moving body; and the moving bodylocation detection unit is configured to calculate the moving bodylocation information based on the shape information, history of themoving body location information and the moved distance of the movingbody measured by the moving distance meter.
 5. The inspection deviceaccording to of claim 1, further comprising: a distance meter formeasuring distance to the stator, the distance meter being installed onthe moving main body, wherein the arm driver is configured to drive thearms, at least partly based on distance between the distance meter andthe stator measure by the distance meter.
 6. The inspection deviceaccording to claim 1, further comprising: a camera for obtaining imageincluding image of the stator, the camera being installed on the movingmain body, wherein the arm driver is configured to drive the arms, atleast partly based on the image obtained by the camera.
 7. Theinspection device according to claim 1, wherein at least one of theleast one detector is attached to a tip of at least one of the at leasttwo arms.
 8. The inspection device according to claim 1, wherein the atleast two arms include at least three arms, and the arm driver isconfigured to drive the at least three arms so that at least two armsout of the at least three arms are in the pressed positions when themoving main body is disposed in the gap.
 9. An inspection method forinspecting a turbine generator including a rotor main body and a statorfacing outside of the rotor main body, the method comprising: a movingstep of moving a moving main body on and along the rotor main body,while the moving main body is disposed in a gap between the rotor mainbody and the stator; an arm driving step of driving at least two armsattached to the moving main body so that the at least two arms eachselectively takes a pressed position where the arm extends toward thestator to be pressed to the stator, and a detached position where thearm is detached from the stator; and an inspection step of inspecting atleast one of the rotor main body and the stator, by at least onedetector attached to at least one of the moving main body and the arms,wherein the arm driving step is conducted while at least one of the atleast two arms are maintained in the pressed position, the moving bodyis connected with a cable extending an outer direction of the gap, thecable connected at an end of the moving main body, first and secondsprings are attached to the moving main body, each of the first andsecond springs biasing each arm for expanding toward the stator in astate that each arm contacts the stator and that is inclined toward adirection opposite to the end of the moving body, the arm driver drivesthe arms so that the arms each selectively takes the pressed positionand the detached position, when the arm driver is operable, the movingmain body moves itself on and along the rotor main body, while the mainbody moves and before one of the arms strikes a baffle of the stator,one of the arms is located in the detached position by the arm driveragainst a force of the first spring and the other arm is maintained tocontact the stator by a force of the second spring, and when the armdriver is inoperable, the moving main body is pulled out of the gap bythe cable on and along the rotor main body and when the arm strikes thebaffle, one of the arms is pushed down toward the rotor main body by thebaffle pushing the inclination of one of the arms against a force of thefirst spring and the other arm is maintained to contact the stator by aforce of the second spring.